Utility

An invention must be useful, otherwise it is not an invention within the meaning of the Patent Act. This is sometimes referred to as the utility requirement.

invention means any new and useful art, process, machine, manufacture or composition of matter, or any new and useful improvement in any art, process, machine, manufacture or composition of matter; [Emphasis added.]

The Supreme Court of Canada in AZT referred to the public interest in:

1. avoiding cluttering the public domain with useless patents, and granting monopoly rights in exchange for misinformation or speculation; and
2. early disclosure of inventions, even before their utility has been fully verified by tests.

With respect to the first point, granting useless patents and monopoly rights for misinformation has a chilling effect on other researchers and impedes others in their search for a real solution to the same problem. Moreover, it would be unfair to the public to grant monopoly rights in exchange for misinformation or speculation, since the public receives nothing useful in return. In the case of speculation, the inventor is offering nothing to the public but wishful thinking in exchange for locking up potentially valuable research turf. Speculative patents, if permitted, would turn the patent system into a lottery that rewards those with deep pockets.

With respect to the second point, not only is the early disclosure of inventions is in the public interest, but it would be unfair to a patentee to require the patentee to demonstrate an invention’s usefulness through tests.

The concept of sound prediction, in which utility can be predicted in advance of complete testing, balances these competing public interests. Predicted utility requires that the invention must not have been a lucky guess or mere speculation at the time the inventor filed for the patent.

3 … For the Commissioner of Patents to have allowed Glaxo/Wellcome a patent based on speculation would have been unfair to the public. For him to have required Glaxo/Wellcome to demonstrate AZT’s efficacy through the clinical tests required by the Minister of Health for approval of a new drug for medical prescription would have been unfair to Glaxo/Wellcome. The disclosure made in the patent was and is of real use and benefit … . The fact remains that Glaxo/Wellcome, by making the disclosure, has fulfilled its side of the bargain with the public, and is by law entitled to legal protection for what it has disclosed.

…

37 A patent, as has been said many times, is not intended as an accolade or civic award for ingenuity. It is a method by which inventive solutions to practical problems are coaxed into the public domain by the promise of a limited monopoly for a limited time. Disclosure is the quid pro quo for valuable proprietary rights to exclusivity which are entirely the statutory creature of the Patent Act. Monopolies are associated in the public mind with higher prices. The public should not be expected to pay an elevated price in exchange for speculation, or for the statement of any mere scientific principle or abstract theorem (s. 27(3)), or for the discovery of things that already exist, or are obvious. The patent monopoly should be purchased with the hard coinage of new, ingenious, useful and unobvious disclosures.

…

45 … The grant of a patent monopoly for 17 years (20 years after October 1, 1989) creates, and is intended to create, serious anti-competitive effects. Once the subject matter of the patent is fenced in by the claims, others trespass (advertently or inadvertently) on the forbidden territory at their peril. The boundary is defended by a considerable arsenal of remedies conferred by the Patent Act, including an accounting of the infringer’s profits in an appropriate case. Patent litigation is usually protracted and costly. (The present litigation commenced in 1990 and took 12 years to get here.) There is in the meantime a chilling effect on other researchers. They will tend to invest their talents in less litigious areas. Parliament considered this chilling effect to be a worthwhile price for the disclosure of a new and useful invention, bringing into the public domain information that might otherwise remain a trade secret, but there is nothing in the Act to suggest that Parliament was prepared to accept the chilling effect in exchange for nothing but speculation.

46 Glaxo/Wellcome argues that where the subject matter of the patent is a new use for an old chemical compound, it is enough that the invention is reduced to a definite and practical shape by the formulation of a written or oral description. This cannot be correct. The concept might be beautifully described but at the same time be quite wrong and misleading to people who consult it. In such a case, the public would be spending its monopoly rights for misinformation, and in the process litter the patent registry with useless patents that might impede others in their search for a real solution to the same problem.

…

52 … Glaxo/Wellcome claimed a hitherto unrecognized utility but if it had not established such utility by tests or sound prediction at the time it applied for its patent, then it was offering nothing to the public but wishful thinking in exchange for locking up potentially valuable research turf for (then) 17 years. …

…

55 In the present case, by contrast, if the utility of AZT for the treatment of HIV/AIDS was unpredictable at the time of the patent application, then the inventors had not made an invention and had offered nothing to the public in exchange for a 17-year monopoly except wishful thinking.

…

66 The doctrine of sound prediction balances the public interest in early disclosure of new and useful inventions, even before their utility has been verified by tests (which in the case of pharmaceutical products may take years) and the public interest in avoiding cluttering the public domain with useless patents, and granting monopoly rights in exchange for misinformation.

…

69 With respect, I think Parliament intended to get something more than speculation in exchange for the grant of a patent monopoly (a point which is further discussed below). On the other hand, I do not think, with respect, that the doctrine of sound prediction is limited to the narrow ambit ascribed to it by the trial judge. Once it is accepted that in appropriate circumstances utility can be predicted in advance of complete testing (whether of untested chemical compounds or otherwise), there seems no reason in principle why the doctrine should not be applied more generally, depending, of course, on the expert evidence. There is no doubt that care must be taken that the doctrine is not abused, and that sound prediction is not diluted to include a lucky guess or mere speculation. The public is entitled to obtain a solid teaching in exchange for the patent rights.

…

80 In my view, with respect, Glaxo/Wellcome’s proposition is consistent neither with the Act (which does not postpone the requirement of utility to the vagaries of when such proof might actually be demanded) nor with patent policy (which does not encourage the stockpiling of useless or misleading patent disclosures). Were the law to be otherwise, major pharmaceutical corporations could (subject to cost considerations) patent whole stables of chemical compounds for all sorts of desirable but unrealized purposes in a shot-gun approach hoping that, as in a lottery, a certain percentage of compounds will serendipitously turn out to be useful for the purposes claimed. Such a patent system would reward deep pockets and the ingenuity of patent agents rather than the ingenuity of true inventors.

…

84 … In the broader context of the Patent Act, as well, there is good reason to reject the proposition that bare speculation, even if it afterwards turns out to be correct, is sufficient. An applicant does not merit a patent on an almost-invention, where the public receives only a promise that a hypothesis might later prove useful; this would permit, and encourage, applicants to put placeholders on intriguing ideas to wait for the science to catch up and make it so. The patentee would enjoy the property right of excluding others from making, selling, using or improving that idea without the public’s having derived anything useful in return.

[Emphasis in original.]

The purpose of the utility requirement is to prevent the patenting of fanciful, speculative or inoperable inventions.

[56] The utility requirement serves a clear purpose. To avoid granting patents prematurely, and thereby limiting potentially useful research and development by others, the case law has imposed a requirement that an invention’s usefulness be demonstrated or soundly predicted at the time of application, rather than at some later point. This ensures patents are not granted where the use of the invention is speculative. What matters is that an invention be useful, in the sense that it carries out some useful known objective and is not merely a laboratory curiosity whose only possible claim to utility is as a starting material for further research (Re Application of Abitibi Co. (1982), 62 C.P.R. (2d) 81 (Patent Appeal Board and Commissioner of Patents), at p. 91).

[57] The application of the utility requirement in s. 2, therefore, is to be interpreted in line with its purpose — to prevent the patenting of fanciful, speculative or inoperable inventions.

The Supreme Court of Canada in AstraZeneca set out the correct approach to utility. A two-step analysis should be undertaken to determine whether an invention has sufficient utility:

1. identify the subject-matter of the invention as claimed in the patent; and
2. ask whether that subject-matter is useful — is it capable of a practical purpose (i.e. an actual result)?

(2) The Correct Approach to Utility

[52] The words in s. 2 of the Act ground the type of utility that is pertinent by requiring that it is the subject-matter of an invention or improvement thereof that must be useful. For the subject-matter to function as an inventive solution to a practical problem, the invention must be capable of an actual relevant use and not be devoid of utility. As stated by Justice Binnie in AZT, a patent is a method by which inventive solutions to practical problems are coaxed into the public domain by the promise of a limited monopoly for a limited time (para. 37 (emphasis added)).

[53] Utility will differ based on the subject-matter of the invention as identified by claims construction. Thus, the scope of potentially acceptable uses to meet the s. 2 requirement is limited — not any use will do. By requiring the usefulness of the proposed invention to be related to the nature of the subject-matter, a proposed invention cannot be saved by an entirely unrelated use. It is not sufficient for an inventor seeking a patent for a machine to assert it is useful as a paperweight.

[54] To determine whether a patent discloses an invention with sufficient utility under s. 2, courts should undertake the following analysis. First, courts must identify the subject-matter of the invention as claimed in the patent. Second, courts must ask whether that subject-matter is useful — is it capable of a practical purpose (i.e. an actual result)?

Justice Brown was of the opinion that utility is to be determined on a claim-by-claim basis.

[325] AstraZeneca states at para 53 that utility will differ based on the subject-matter of the invention as identified by claims construction. Utility is assessed on a claim by claim basis after AstraZeneca as it was before AstraZeneca: AstraZeneca v Apotex, 2015 FCA 158, paras 4 and 5, and Apotex v Pfizer, 2014 FCA 250, in accordance with s 58 of the Patent Act and para 46 of AstraZeneca itself.

[326] Therefore the utility analysis will proceed on a claim by claim basis …

Justice McVeigh was of the opinion that utility is not to be determined on a claim-by-claim basis. Rather, the utility analysis looks at the patent as a whole.

[120] Whether utility is assessed claim-by-claim or based on the whole patent requires some discussion. First, AstraZeneca says that the subject matter of the proposed invention is to be determined, not the subject matter of each claim. Logically, the subject matter of the patent stays consistent throughout the claims. In addition, the statutory wording of section 2 of the Patent Act is unlike that of 28.2 and 28.3 — wording which previously led the courts to determine that obviousness and novelty are assessed on a claim-by-claim basis. Therefore, the utility analysis looks at the patent as a whole.

An invention is not useful if it will not work.

There is a helpful discussion in Halsbury’s Laws of England, (3rd ed.), vol. 29, at p. 59, on the meaning of not useful in patent law. It means that the invention will not work, either in the sense that it will not operate at all or, more broadly, that it will not do what the specification promises that it will do. There is no suggestion here that the invention will not give the result promised. The discussion in Halsbury’s Laws of England, ibid., continues:

… the practical usefulness of the invention does not matter, nor does its commercial utility, unless the specification promises commercial utility, nor does it matter whether the invention is of any real benefit to the public, or particularly suitable for the purposes suggested. [Footnotes omitted.]

and concludes:

… it is sufficient utility to support a patent that the invention gives either a new article, or a better article, or a cheaper article, or affords the public a useful choice. [Footnotes omitted.]

Canadian law is to the same effect. … [p. 525]

The invention must be capable of an actual relevant use. Not any use will do. By requiring the usefulness of the proposed invention to be related to the nature of the subject-matter, a proposed invention cannot be saved by an entirely unrelated use. It is not sufficient for an inventor seeking a patent for a machine to assert it is useful as a paperweight.

A single use related to the nature of the subject-matter is sufficient. Moreover, an invention’s usefulness must be demonstrated or soundly predicted at the time of application.

[52] … For the subject-matter to function as an inventive solution to a practical problem, the invention must be capable of an actual relevant use and not be devoid of utility. As stated by Justice Binnie in AZT, a patent is a method by which inventive solutions to practical problems are coaxed into the public domain by the promise of a limited monopoly for a limited time (para. 37 (emphasis added)).

[53] Utility will differ based on the subject-matter of the invention as identified by claims construction. Thus, the scope of potentially acceptable uses to meet the s. 2 requirement is limited — not any use will do. By requiring the usefulness of the proposed invention to be related to the nature of the subject-matter, a proposed invention cannot be saved by an entirely unrelated use. It is not sufficient for an inventor seeking a patent for a machine to assert it is useful as a paperweight.

…

[55] The Act does not prescribe the degree or quantum of usefulness required, or that every potential use be realized — a scintilla of utility will do. A single use related to the nature of the subject-matter is sufficient, and the utility must be established by either demonstration or sound prediction as of the filing date (AZT, at para. 56).

[56] … [T]he case law has imposed a requirement that an invention’s usefulness be demonstrated or soundly predicted at the time of application, rather than at some later point. This ensures patents are not granted where the use of the invention is speculative. …

There is no need to resort to sound prediction when the utility of the invention had been demonstrated.

Sound prediction is a concept that becomes relevant only when an invention’s utility cannot actually be demonstrated by way of tests or experiments, but can nevertheless be successfully predicted: see, e.g., AZT. [para. 37]

Justice Binnie articulated what was required to establish sound prediction, emphasizing that it consisted of three components, all of which must be met by a patent: first, a factual basis for the prediction; second, an articulable and sound line of reasoning from which the desired result can be inferred from the factual basis; and third, proper disclosure.

5. The Requirements of the Doctrine of Sound Prediction

70 The doctrine of sound prediction has three components. Firstly, as here, there must be a factual basis for the prediction. In Monsanto and Burton Parsons, the factual basis was supplied by the tested compounds, but other factual underpinnings, depending on the nature of the invention, may suffice. Secondly, the inventor must have at the date of the patent application an articulable and sound line of reasoning from which the desired result can be inferred from the factual basis. In Monsanto and Burton Parsons, the line of reasoning was grounded in the known architecture of chemical compounds (Monsanto, at p. 1119), but other lines of reasoning, again depending on the subject matter, may be legitimate. Thirdly, there must be proper disclosure.

In Monsanto, Justice Pigeon, writing for the majority, drew the conclusion that a sound prediction of usefulness does not amount to a certainty of usefulness. There can be a risk that a sound prediction turns out to be wrong.

I have quoted again the passage quoted by the [Patent Appeal] Board because I consider the last sentence of the paragraph of some importance as it does clearly indicate what is meant by a sound prediction. It cannot mean a certainty since it does not exclude all risk that some of the area covered may prove devoid of utility. It thus appears to me that the test formulated by Graham J. [in Olin Mathieson Chemical Corp v Biorex Laboratories Ltd, [1970] RPC 157 (Ch D)] involves just two possible reasons for rejecting claims such as those in issue.

1. There is evidence of lack of utility in respect of some of the area covered;
2. It is not a sound prediction.

[p. 1117]

The invention must be useful as of the filing date based on the information and expertise then available. Evidence and knowledge available after the filing date cannot establish utility. Patents are not granted where the use of the invention is speculative. Bare speculation, even if it afterwards turns out to be correct — a lucky guess, is not an invention.

46 … Nor, in my view, is it enough for a patent owner to be able to buttress speculation with post-patent proof, and thereby to turn dross into gold. If a patent sought to be supported on the basis of sound prediction is subsequently challenged, the challenge will succeed if the prediction at the date of application was not sound, or, irrespective of the soundness of the prediction, there is evidence of lack of utility in respect of some of the area covered.

…

56 Where the new use is the gravamen of the invention, the utility required for patentability (s. 2) must, as of the priority date, either be demonstrated or be a sound prediction based on the information and expertise then available. …

…

79 The after-the-fact validation theory was accepted by the Federal Court of Appeal, at para. 51:

In other words, so long as an inventor can demonstrate utility or a sound prediction at the time a patent is attacked, the patent will not fail for lack of utility. The time at which usefulness is to be established is when required by the Commissioner of Patents or in court proceedings when the validity of the patent is challenged on that ground.

80 In my view, with respect, Glaxo/Wellcome’s proposition is consistent neither with the Act (which does not postpone the requirement of utility to the vagaries of when such proof might actually be demanded) nor with patent policy (which does not encourage the stockpiling of useless or misleading patent disclosures). Were the law to be otherwise, major pharmaceutical corporations could (subject to cost considerations) patent whole stables of chemical compounds for all sorts of desirable but unrealized purposes in a shot-gun approach hoping that, as in a lottery, a certain percentage of compounds will serendipitously turn out to be useful for the purposes claimed. Such a patent system would reward deep pockets and the ingenuity of patent agents rather than the ingenuity of true inventors.

…

84 … In the broader context of the Patent Act, as well, there is good reason to reject the proposition that bare speculation, even if it afterwards turns out to be correct, is sufficient. An applicant does not merit a patent on an almost-invention, where the public receives only a promise that a hypothesis might later prove useful; this would permit, and encourage, applicants to put placeholders on intriguing ideas to wait for the science to catch up and make it so. The patentee would enjoy the property right of excluding others from making, selling, using or improving that idea without the public’s having derived anything useful in return.

Relying on AZT, Justice Mactavish observed that commercial value is of no assistance in determining the soundness of the prediction.

[157] There is no question that the ’206 patent turned out to be a very useful invention. However, this sort of after the fact validation was specifically rejected by the Supreme Court of Canada in Wellcome. Thus, the fact that three compounds within the ’206 patent later turned out to have commercial value is of no assistance in determining the soundness of the prediction at the time in question: see Wellcome, supra, para. 78-85.

Justice LeBel, in Viagra, noted that commercial success is relevant to whether an invention is useful.

[41] In any event, Pfizer disclosed the utility of sildenafil by disclosing that tests had been conducted. Sildenafil was found to be useful before the priority date, which means that the requirement in AZT is met. Further, [e]vidence as to utility may be found in the reception of the invention by the public. Enthusiastic reception by those to whom it is directed will tend to indicate that the invention is useful: Perry and Currier, at §7.12.

Justice Rothstein, at a hearing for leave to appeal, raised the issue of whether market acceptance, or after-the-fact evidence, would have some bearing on the utility of a patent. He noted that the court in Viagra indicated that [e]vidence as to utility may be found in the reception of the invention by the public. Justice Rothstein observed this suggests that perhaps the door is open to after-the-fact market evidence as to utility and as to the advantage of the selection patent.

Justice Rothstein reviewed what the Supreme Court of Canada said in AZT and Viagra about evidence of utility.

Back in 2002, the Supreme Court decided the AZT case, Apotex v Wellcome. The case dealt with sound prediction as the basis for proving the utility of an invention. In AZT, the court said to prove utility, an invention must be soundly predicted at the time of the patent application. Of course, at that date the invention would not have been marketed, so there would be no evidence of market acceptance. However, in the Viagra case, decided just last year, our Court said that evidence of utility may be found in the reception of the invention by the public.

[28:23 minute mark]

In commenting on the application for leave to appeal from the judgment of the Federal Court of Appeal in Eli Lilly Canada Inc v Novopharm Limited, 2012 FCA 232, to the Supreme Court of Canada, he observed that it was somewhat anomalous that a court should find that Lilly’s drug, which was successfully received in the market, lacked utility. He was of the opinion that if the AZT case is to be interpreted as precluding the evidence of market acceptance to prove sound prediction, perhaps it is worth looking at in an appeal before the Supreme Court of Canada, but that was not Lilly’s argument on leave.

Well, there’s no doubt that Plavix has been very successfully received in the market, which makes it somewhat anomalous that a court should find that Lilly’s invention of Plavix lacks utility. [Note: the drug in question was olanzapine and not Plavix.] So there’s an argument to be made, that if the AZT case is to be interpreted as precluding the evidence of market acceptance to prove sound prediction, perhaps it is worth looking at. However, that wasn’t Lilly’s argument on leave.

[29:09 minute mark]

The Commissioner of Patents must justify any refusal to grant a patent. The Commissioner cannot refuse to grant a patent on the basis of a lack of sound prediction unless there is evidence that the prediction is not sound and reasonable.

Although the report of the Board is quite lengthy, in the end with respect to claim 9 all it says after stating the principle with which I agree, is that a claim has to be restricted to the area of sound prediction and we are not satisfied that three specific examples are adequate. As to why three is not enough nothing is said. … [I]t is important to note that s. 42 of the Patent Act reads:

42. Whenever the Commissioner is satisfied that the applicant is not by law entitled to be granted a patent he shall refuse the application and, by registered letter addressed to the applicant or his registered agent, notify the applicant of such refusal and of the ground or reason therefor.

I have underlined by law to stress that this is not a matter of discretion: the Commissioner has to justify any refusal.

…

In the instant case, the Board, in spite of a complete absence of any evidence of unsoundness of the prediction, deny the claims and would in the end limit them to the area of proved utility instead of allowing them to the extent of predicted utility. In my view this is contrary to s. 42 of the Patent Act.

Under that section the Commissioner is instructed to refuse the patent when satisfied that the applicant is not by law entitled to it. Here what he has said in approving the decision of the Board is in effect I am not satisfied you are entitled to it. In my opinion the Commissioner cannot refuse a patent because the inventor has not fully tested and proved it in all its claimed applications. This is what he has done in this case by refusing to allow claims 9 and 16 unless restricted to what had been tested and proved before the application was filed. If the inventors have claimed more than what they have invented and included substances which are devoid of utility, their claims will be open to attack. But in order to succeed, such attack will have to be supported by evidence of lack of utility. At present there is no such evidence and there is no evidence that the prediction of utility for every compound named is not sound and reasonable.

[pp. 1118-1119 and 1121-1122.]

In AZT, the Supreme Court of Canada interchangeably referred to the application date and priority date as the date to be used in evaluating the soundness of the inventor’s prediction. This created in some uncertainty in which date should be used.

Here, the Federal Court reviewed AZT and concluded that the proper date for assessing sound prediction is the Canadian filing date and not the priority date.

[88] There was much debate between the parties at the hearing as to the proper date to be used to assess the soundness of the prediction …

[89] This issue is important, as the soundness of a prediction is to be assessed based upon the information and expertise available at the relevant time. …

[90] The parties all rely on the Supreme Court’s decision in the Wellcome case to support their respective positions regarding the relevant date.

[91] A review of the Wellcome decision discloses that there was no debate between the parties as to the appropriate date for assessing the soundness of the prediction in issue, and, perhaps as a result of this, the phrases application date and priority date are used virtually interchangeably in the decision. By way of example, at paragraphs 3, 56, 71 and 72, Justice Binnie refers to the priority date as being the date to be used in evaluating the soundness of the inventor’s prediction, whereas in paragraphs 46, 55 and 97 reference is made to the date of the Canadian application as being the relevant date.

[92] However, it is in paragraph 70 of the decision that the Court sets out the tripartite test for sound prediction, explicitly stating that [T]he inventor must have at the date of the patent application an articulable and sound line of reasoning from which the desired result can be inferred from the factual basis.

[93] Thus, while the issue is not free from doubt, it appears that the Wellcome test contemplates that the Canadian filing date be used for the purposes of assessing the soundness of the prediction.

The Federal Court of Appeal affirmed that the relevant date is the filing date.

[30] I am in agreement with Justice Mactavish that the relevant date is the Canadian filing date, in this case, October 20, 1981. It is the time which is most reasonable in achieving consistency in the application of the three components of the Wellcome test.

The Supreme Court of Canada referred to the filing date as the date on which utility must be established.

[55] … the utility must be established by either demonstration or sound prediction as of the filing date (AZT, at para. 56).

[56] … the case law has imposed a requirement that an invention’s usefulness be demonstrated or soundly predicted at the time of application, rather than at some later point. …

The Federal Court of Appeal reaffirmed that the relevant date for assessing utility is the Canadian filing date and not the priority date.

[32] … [The Federal Court] erroneously selected the priority date of the 932 patent of April 15, 1999 as being the relevant date for assessing utility when the correct date for the assessment of utility ought to have been the Canadian filing date (see Aventis Pharma Inc. v. Apotex Inc., 2006 FCA 64 at para. 30, 46 C.P.R. (4th) 401).

The Supreme Court of Canada reasserted that even though utility of the subject-matter is a requirement of patent validity, a patentee is not required to disclose the utility of the invention in the patent to fulfill the requirements of section 2 of the Patent Act. The disclosure requirement in subsection 27(3) is independent of the requirement in section 2 that an invention be useful.

[42] Section 27(3) of the Act provides that in the specification, a patentee must describe the invention with sufficiently complete and accurate details as will enable a workman, skilled in the art to which the invention relates, to construct or use that invention when the period of the monopoly has expired (Whirlpool, at para. 42, quoting Consolboard, at p. 517).

[43] There is a difference between the requirement in s. 2 that an invention be useful and the requirement to disclose an invention’s operation or use as per s. 27(3). As explained by Dickson J. (as he then was) in Consolboard, the former is a condition precedent to an invention and the latter a disclosure requirement, independent of the first:

… the Federal Court of Appeal erred also in holding that s. 36(1) [now s. 27(3) and (4)] requires distinct indication of the real utility of the invention in question. There is a helpful discussion in Halsbury’s Laws of England (3rd ed.), vol. 29, at p. 59, on the meaning of not useful in patent law. It means that the invention will not work, either in the sense that it will not operate at all or, more broadly, that it will not do what the specification promises that it will do. There is no suggestion here that the invention will not give the result promised. …

…

… the Federal Court of Appeal has confused the requirement of s. 2 of the Patent Act defining an invention as new and useful, with the requirement of s. 36(1) [now s. 27(3)] of the Patent Act that the specification disclose the use to which the inventor conceived the invention could be put. The first is a condition precedent to an invention, and the second is a disclosure requirement, independent of the first. [Emphasis added.]

(Consolboard, at pp. 525 and 527)

…

[58] Even though utility of the subject-matter is a requirement of patent validity, a patentee is not required to disclose the utility of the invention to fulfill the requirements of s. 2. As was stated by Dickson J. in Consolboard:

… I do not read the concluding words of s. 36(1) [now s. 27(4)] as obligating the inventor in his disclosure or claims to describe in what respect the invention is new or in what way it is useful. He must say what it is he claims to have invented. [p. 526]

See also Teva, at para. 40.